All radial arm saws currently available utilize a chipboard platen securely mounted to the support frame of a saw. Movable spacers and clamps are usually employed to mount a guide fence at different positions on the platen. The space between the guide fence and saw blade correspondences to the cut width made to a work piece. However, the clamp-and-cut adjustment method provides only gross adjustments and not fine adjustments.
A second deficiency with current radial arm saws is difficulty in making a small change to the kerf of a rip-cut. Prior art teaches slight adjustments can be made to the position of the saw blade such that the saw blade is no longer parallel to the guide fence. Accordingly, when a work piece is slid along the guide fence into the nonparallel saw blade, the kerf made will be larger than if the saw blade was parallel. However, precise and accurate increases to the kerf are not possible with the prior art. The saw blade is mounted to a saw carriage which is locked to rails which overhang the platen. The saw carriage is mounted to overhanging rails by a threaded stud and knob. When a small change in the kerf is required, the knob is loosened, the carriage rolled a small amount, and the knob retightened. However, the retightening of the knob itself, will sometimes move the carriage and change the cut aspect of the saw blade, thus changing the kerf. In addition, the scale on the overhanging rails is generally unreliable for changes less than 1/32 of an inch.
In addition, it is difficult to ensure the guide fence is parallel to the saw blade using the clamp-and-cut method. Ensuring the guide fence and saw blade are parallel is important for two reasons: it reduces the chance of kick-back, and reduces the chance of chipping and scarring the finish the work piece along the cut.
Each of these radial arm saw deficiencies was summarized in an article entitled "Coping with your Radial Arm Saw" published in the July/August 1989 issue of The Woodworkers Journal, which stated "most woodworkers thoroughly distrust radial arm saws. The saws are so notoriously sloppy that shops often only use them for rough work". Accordingly, it would be advantageous to provide a device which adapts radial arm saws to perform precise and accurate cuts and that can accurately and precisely adjust the kerf of the saw.